Refining process of sugar juice by chlorination



mama July 6, 19 26.

UNITED STATES PATENT OFFICE,-

sauicmo com, or rovornm, AND no towns, or mums, urm. nnrmme rnocnss or soon cures IEY canonnurron.

No Drawing.

This invention relates to a process for the refinin of sugar juice by chlorination, more articu arly to a process comprising the folowing successive steps, that is, chlorination of sugar juice or liquid raw sugar by blowing 0 lorine gas intosugar juice or liquid at a temperatureof not more than C., removing the active chlorine and neutralization of the treated juice by adding an alkaline material. It has for its object the decomposition of the colouring elements and other impurities contained. in the juice by oxidizing action of active chlorine, so that the said juice isbleached and refined more easily and more economically than by any other recess hitherto known.

In is specification and claims, the word juice should be understood to mean that extracted or taken from sugar canes, beet roots and/or other sacchariferous plants, or li uid of raw su ar made of such juice.

efore explainm the details separately under each particu er, a general explanation is here attempted. The process generally speakin is firstly to generate active chlorine in e juice to be treated, by blowing chlorine gas therein or by the like manner. Keeping the juice at a temperature of not more an 55 0., bleaching and refining of the juice to be completed while retaining it in acidic or neutral state. Seeondly, activated charcoal is added in order to remove active chlorine. and thirdly or lastly, an alkaline material is added to the juice to neutralize the same in such a degree as not to invite or prompt the formation of invert sugar. The uice thus refined may be treated to manufacture sugar b a method publicly known in the sugar in ustry.

Ghemically speakiu it may be observed that the infusion of c lorine in sugar juice may stimulate the inversion of sucrose as hydrochloric acid develops therein as well as active chlorine, and that the heat treat ment of the solution that has become acidic will turn all the sucrose in the solution to I invert ear and destroy the attainment of the purpose,.but the inventors practical experience has clonstrated that such inversing effect is almost nil, when the quantity ct active chlorine used is so small as to just complete the bleaching with the heat so arranged as to be kept constantly below 55 Q, and even if more or ism inversion takes a ace, such inversion is in no do appreenmve from industrial point 0 view. it

Application filed December a, mu. eel-m no. issue is to be noted that the bleaching is perfectly accomplished in the above degree of heat;

any stronger heat being found neither to improve nor to accelerate the b caching.

ollowing the bleaching treatment already explained, it is now necessary to remove the chlorine which remains without participating in the bleaching o oration, as otherwise it will client or 'sturb the process of neutralizin i viich follows. The method of active ch orine removal is 8t, tained b the aid of the catal 0 action of activate charcoal, or any 0 er carbonifr erous's'u'bstances of porous construction capableof catalytic action.

After disposing of the chlorine as de scribed before, the next operation is to neutralize the solution b mixing an line agent-in the same. is operation must be done immediately afterthe above chlorine treatment as otherwise, if the solution is ina stron ly acidic state, it will be turned into inverte sugar in the course of the subsequent operation, while if the solution is in alkaline state, the bleached solution will showa brownish colour. The material to be used for neutralization of the solution may be an alkaline substance, such as oxides, or car onate of alkali or-alkaline earth material, or ammonia. The neutralizing agents may be added to the juice or solution after the infusion of chlorine, or may be added partly or wholly from the commencement of the treatment or during its course.

With respect to the use of chlorine, it is to be notedthat while blowing it in the form of gas into sugar juice or llquid raw su I r is found most convenient, any of the ollowing solutions may be substituted for a part or whole of chlorine gas blowing,

namely, water solution of chlorine, sugar juice solution of chlorine, acidic or neutral solution prepared by dissolving chlorine in a solution of alkali, such as lime, acidic or neutral solution prepared by adding acidic substance, such as chlorine or carbon-dioxide to the water solution of bleaching owder, or the like which contains active lorine. 0r, chlorine gas may be successively generated in the juice by direct'electric current through the same reviously mixed with a .quantity of chlori e such as sodium chloride. Foregoing processes are illustrated by a few examples as follows.

Ec2cmple 1.-A solution consistin of kilogrammes of raw sugar, having t e shade evaporated in vacuum, by ordinary method. r

Care should be taken at the same time, that the bleaching solution described above may not become alkaline in property.

An advantage may be gained in carrying out the method above described in the economy of chlorine when the sugar to be treated is to treat the raw sugar after having been washed in water so as to remove the molasses adhering or stuck to the material: but as it results in reducing the organic acid salt in them, such method requires very great care, at the time of the last neutralization: for if by carelessness or neglect the treatment to be given in acidic state however slight it may be, the loss will be greater than by the treatment in which molasses have not been removed.

It is to be noted that incarrying out the bleaching according to the process above stated, a quantity of chlorine less than that indicated in the above example 1 may be so used as to have the juice in semi-bleached condition and in such condition to be filtered through a charcoal filter. Or, the treatment may be reversed, that is to say, the juice may be first filtered and then the bleaching process according to the example above cited ma be applied. In both cases'described, it wil be found that the bleaching will be far more easily accomplished compared with other chlorination methods.

E wample 2.In applying the chlorination process to the sugar juice in the condition as it is extracted from sugar cane or other sacchariferous plants, this invented process is perfectly carried out in combination with other refining methods such as defectation, sulfitation, and carbonization. For instance, a small quantity of chlorine gas blown into the cane 'uice kept at a temperature lower than 40 will make the impure matters coagulate and precipitate after which the juice is filtered, and activated charcoal is mixed in order to remove active chlorine. 'Aiter the chlorine is thus removed, phosphate or carbonization process may be resorted to, and manufacturing follows in a usual way. The quantity of chlorine to be blown into the juice varies greatly according to the quality of sugar juice and also depends upon whether or not a previous treatment was given. Taking cane juice as anexample, 0.01 to 0.02 kilogramme of chlorine to 100 litres of the juice is sufiicient for the purpose of refining. It is to be added that the above treatment maybe made with success to the juice concentrated up to a certain stage of refining.

Example 3.Bleachin of the juice pre viously refined by an or inary method can be perfectly made by adding a suitable quantity of clear solution of bleaching powder,

into which chlorine gas is blown, the temperature being kept to one degree below 40 C. to make the juice acidic or neutral state. Following this treatment, activated charcoal is added and the resulting precipitate is filtered. If the product is found to be acidic, it should be neutralized by the addition of slaked lime.

EmampZe-4.The passing of direct electric current between electrodes of platinum or graphite through 100 litres of liquid raw sugar or juice whether in the original condition or a concentrated form with 0.03 kilogramme of sodium chloride added, will generate chlorine by electrolysis and the bleaching is thereby perfected. To the materials thus bleached, 0.05 to 0.01 kilogramme of activated charcoal is added and after being neutralized, manufacturing is carried out by following usual methods.

What we claim is 1. A process of refining sugar juice comprising the combination of the following successive ste s, chlorination of sugar juice by blowing c lorine gas into the same at a temperature of not more than 55 (1, removing the active chlorine therefrom and neutralization of the treated juice by addition of an alkaline substance.

2. A process of refining sugar julce comprising the combination of the following successive steps, blowing chlorine gas in sugar juice at a temperature of not more than 55? (3., removing the chlorine therefrom by adding activated charcoal and neutralization of the treated juice by addition of an alkaline substance.

In testimony whereof we have signed our names to this specification.

FUSAZIRO KOTERA. SHUICHIRO OCHI. 

